The present invention relates to a reflector used in a strobe device.
In a strobe device used in a camera, most of the light is directed towards an object to be photographed. Further, since the field of view of a photographing lens used in the camera is fairly narrow, the strobe device only needs to provide a beam of light which will provide sufficient illumination over the field of view of the photographing lens.
Some strobe devices are provided with reflectors, in order that more of the light emitted by the light source is directed towards the object to be photographed. Therefore, some of the light emitted by the light source is directly incident on the object, while the remaining light is first reflected by the reflector and then incident on the object.
Conventionally, the shape of the reflector is such that a cross section, along an optical axis, of the reflector forms a part of an oval. A strobe having a reflector with this type of cross-section reflects the light rays emitted by the light source to form an image of the light source at a certain point in front of the strobe. However, due to the aberration caused by the reflection surface and a converging lens, which may be provided in the light path, the image may be distorted, resulting in the intensity of the light incident on the object being unevenly distributed.
Further, since a reflector having an oval cross-section is difficult to manufacture accurately, various alternatives such as a reflector having a parabolic or hyperbolic cross section, or a reflector composed of sections joined together (an example of which is shown in Japanese Patent Publication H3-48835), have been proposed. However, it is still difficult to verify that the reflector has the proper shape, if these other constructions are employed. Further, even if the shape is verifiable, a sufficient distribution of the illumination from the strobe device may be difficult to achieve.